Recently, optical disks have been selling in large quantities. When a flaw or flaws are made on its surface, it is sometimes impossible to read data from the disk. It is therefore desirable to repair the disk and restore it to a readable state. In view of resource saving, it is not desirable to dispose of such reusable optical disks in large quantities.
Reference is made to FIG. 5, which shows an example of a conventional disk polishing apparatus. The apparatus is composed of a disk rotator A2 for rotating an object 31 and a polishing mechanism B2 for polishing the surface of the object 31. In the polishing mechanism B2, a polishing pad C2 is attached to a rotating substrate 33 fixed to a rotation shaft 32 via such an attachment means as the hook-and loop fastener VELCRO™. In the polishing pad C2, a polishing sheet 36 is attached to the bottom of a spongy elastic body 35.
Reference is made to FIG. 6a, which shows the case of polishing the surface of an optical disk with the above-constructed polishing apparatus. When the elastic body 35 of the polishing pad C2 is too soft, deformation occurs in the polishing face. Thus, in the course of polishing, roundness E is formed on the outer edge of the optical disk 31.
When, on the other hand, the elastic body 35 of the polishing pad C2 is not pliable, the pressure contact between the polishing face and the surface of the optical disk is tightened in part. It is therefore difficult to eliminate abrasive filings (e.g. polycarbonate powder), which clog the surface of the polishing sheet. Thus, the polishing power decreases and the accumulated filings cause small shallow cuts (i.e. scratches) on the surface of the optical disk.
Further, when the rotation plane of the optical disk is not kept parallel to that of the polishing sheet 36, it is impossible to adequately correct the planar accuracy of the polished face in the course of polishing, as shown in FIG. 6b. 
Accordingly, the problems to be solved by the present invention are as follows: (1) to obtain an appropriate pressure required for polishing; (2) to correct the accuracy of parallelism between the rotation planes of an optical disk and a polishing sheet; (3) to remove roundness formed on the outer edge of an optical disk and unevenness in polishing; and (4) to prevent clogging of the surface of a polishing sheet by the active elimination of abrasive filings and an occurrence of scratches on the surface of an optical disk due to the clogging.